One performance metric of particular interest in solid state storage systems (which is not of interest to other types of storage systems, such as hard disk drives) is write amplification. Write amplification is the ratio of host writes plus overhead writes, compared to host writes alone and is (generally speaking) one measure of the “efficiency” of solid state storage systems. Write amplification is of interest in solid state storage systems because programming and erasing cause the electrical insulation of solid state storage cells to break down, making the cells “leaky” and less able to hold charge for long periods of time. The ideal write amplification value is 1, because no overhead writes are performed when the write amplification value is 1.
It is known that storing hot data with hot data and cold data with cold data in the solid state storage media (i.e., data separation) tends to be better for write amplification. However, techniques which further improve the performance of the system (e.g., which further reduce write amplification) would be desirable.